Mesa (master): draw/clip: fix viewport index for geometry shaders

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: 29ce8060eb0584d619e48c440540adc1f32de76e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=29ce8060eb0584d619e48c440540adc1f32de76e

Author: Dave Airlie <airlied at redhat.com>
Date:   Thu Jul  2 15:37:16 2020 +1000

draw/clip: fix viewport index for geometry shaders

The old code updated the viewport index on the first vertex in
a primitive, however it was picking the first vertex wrong
when used with geometry shaders.

This code has access to the prim info with the primitive lengths
so instead keep track of when a new primitive starts by tracking
the lengths and updating the viewport index then. The prim info
is only valid after a GS or prim assembly, so enable prim assembly
if a vertex shader ever uses viewport index.

This fixes:
piglit arb_viewport_array-render-viewport-2
KHR-GLES31.core.viewport_array.draw_to_single_layer_with_multiple_viewports,Fail
KHR-GLES31.core.viewport_array.draw_mulitple_viewports_with_single_invocation,Fail
KHR-GLES31.core.viewport_array.draw_multiple_layers,Fail
KHR-GLES31.core.viewport_array.depth_range,Fail

Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5489>

---

 .gitlab-ci/piglit/quick_gl.txt                   | 6 ++----
 src/gallium/auxiliary/draw/draw_cliptest_tmp.h   | 7 +++++--
 src/gallium/auxiliary/draw/draw_prim_assembler.c | 3 +++
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/.gitlab-ci/piglit/quick_gl.txt b/.gitlab-ci/piglit/quick_gl.txt
index bc50f08f0f6..6c9f2d8f561 100644
--- a/.gitlab-ci/piglit/quick_gl.txt
+++ b/.gitlab-ci/piglit/quick_gl.txt
@@ -901,7 +901,6 @@ spec/arb_vertex_program/vp-address-02: skip
 spec/arb_vertex_program/vp-address-04: skip
 spec/arb_vertex_type_2_10_10_10_rev/attrib-p-type-size-match: skip
 spec/arb_viewport_array/display-list: skip
-spec/arb_viewport_array/render-viewport-2: fail
 spec/ati_envmap_bumpmap/ati_envmap_bumpmap-bump: skip
 spec/egl 1.4/egl-blob-cache: skip
 spec/egl 1.4/egl-context-priority: skip
@@ -1681,15 +1680,14 @@ spec/oes_texture_view/rendering-formats/render to gl_rgb8ui as gl_rgb8i: skip
 spec/oes_texture_view/rendering-formats/render to gl_rgb8ui as gl_rgb8ui: skip
 spec/oes_texture_view/texsubimage-layers pbo: skip
 spec/oes_texture_view/texsubimage-levels pbo: skip
-spec/oes_viewport_array/render-viewport-2: fail
 wgl/wgl-multi-context-single-window: skip
 wgl/wgl-multi-window-single-context: skip
 wgl/wgl-sanity: skip
 summary:
        name:  results
        ----  --------
-       pass:    21837
-       fail:      217
+       pass:    21839
+       fail:      215
       crash:        0
        skip:     1446
     timeout:        0
diff --git a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
index ba02461db48..b7c77bfd85d 100644
--- a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
+++ b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
@@ -49,7 +49,6 @@ static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
    int viewport_index = 0;
    int num_written_clipdistance =
       draw_current_shader_num_written_clipdistances(pvs->draw);
-   unsigned verts_per_prim = u_vertices_per_prim(prim_info->prim);
 
    if (uses_vp_idx) {
       viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]);
@@ -70,16 +69,20 @@ static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
    }
 
    assert(pos != -1);
+   unsigned prim_idx = 0, prim_vert_idx = 0;
    for (j = 0; j < info->count; j++) {
       float *position = out->data[pos];
       unsigned mask = 0x0;
 
       if (uses_vp_idx) {
          /* only change the viewport_index for the leading vertex */
-         if (!(j % verts_per_prim)) {
+         if (prim_vert_idx == (prim_info->primitive_lengths[prim_idx])) {
+            prim_idx++;
+            prim_vert_idx = 0;
             viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]);
             viewport_index = draw_clamp_viewport_idx(viewport_index);
          }
+         prim_vert_idx++;
       }
       float *scale = pvs->draw->viewports[viewport_index].scale;
       float *trans = pvs->draw->viewports[viewport_index].translate;
diff --git a/src/gallium/auxiliary/draw/draw_prim_assembler.c b/src/gallium/auxiliary/draw/draw_prim_assembler.c
index c0bc145f38b..edaaf0d501f 100644
--- a/src/gallium/auxiliary/draw/draw_prim_assembler.c
+++ b/src/gallium/auxiliary/draw/draw_prim_assembler.c
@@ -76,6 +76,9 @@ draw_prim_assembler_is_required(const struct draw_context *draw,
                                 const struct draw_prim_info *prim_info,
                                 const struct draw_vertex_info *vert_info)
 {
+   /* viewport index requires primitive boundaries to get correct vertex */
+   if (draw_current_shader_uses_viewport_index(draw))
+      return TRUE;
    switch (prim_info->prim) {
    case PIPE_PRIM_LINES_ADJACENCY:
    case PIPE_PRIM_LINE_STRIP_ADJACENCY: